Modem building codes strictly control the types of materials and methods which may be used in building construction. These codes are primarily enacted to ensure that the resulting structures are safe. Failure to comply with the codes often results in the structure not being approved for habitation, and could expose the builder or developer to liability to the buyer. Furthermore, noncompliance results in delays in construction, and increased production costs, due to the time and expense of correcting the mistakes.
In the past few years, the construction industry has gone through major changes. Structures have become more complex, construction schedules are tighter, the labor force generally has no formal training, and there are often language barriers which make it difficult for the labor force to fully understand instructions. Consequently, it has become increasingly difficult to build structures in full compliance with the governing building codes.
The task of ultimately determining whether a structure has been built to code is generally assigned to building inspectors, structural engineers and superintendents. These individuals review a construction site for compliance with architectural blue prints and Uniform Building Codes. The purpose of this inspection is to ensure the safety of the structure by checking that the proper materials/fasteners/construction connectors have been used and in the correct manner.
During the planning of a construction project, the architect will specify certain fasteners and construction connectors based upon their appropriateness to achieve the function they are to perform, and the applicable building codes which govern that type of use. Furthermore, different materials require that different fasteners be applied at specific spacings based on calculations made by the engineers and architect. After these fasteners have been incorporated into the structure by the builder, it is next to impossible for the inspector to know the precise characteristics of the fastener. This is because the portions of the fastener which remain exposed, such as the head of a nail, do not indicate the physical properties of the fastener which may be required by the codes or architect, such as its diameter (or gauge), length, weight, etc. Short of having the fastener removed for inspection, there is often no way to determine this. This problem also exists when verifying that the proper fastener has been used in combination with the proper construction connector, such as plate straps. Consequently, building inspections are more time consuming and costly. There is also increased risk of error, and thus corresponding risk to safety, as the inspector may inadvertently overlook improper fastener or connector uses.
Prior attempts to solve this problem have been unsuccessful. For example, one such attempt is described in U.S. Pat. No. 5,511,917 issued to Charles F. Dickson, the entirety of which is incorporated by reference as if fully set forth herein. The Dickson patent describes a complex system in which numbers and clock like markings are inscribed into nail heads. The markings represent a pattern from which the length and/or gauge of the nail can be identified. However, because the size of the markings is limited by the size of the nail head, for very small nails, the markings cannot be distinguished unless one is within a close proximity (12" maximum) to the nail due to the small size of the inscription. This limits the usefulness of such a marking system, because it would be difficult for building inspectors to determine accurate fastener use from a distance. Further, the Dickson patent states that the nail must be inserted in a specific orientation for the markings to be usable, or that an even more complex marking system providing orientation must be used. Clearly, such complex indicators do not provide the simplification needed by industry and inspectors. Furthermore, the markings taught by Dickson would be distorted by the impact of the driving tool/system, likely making the markings illegible. This system for inscribing distinguishing marks on the nail heads has not been widely adopted, if at all.
Consequently, there exists a need for fasteners and connectors with readily identifiable indicators to determine their physical properties after they have been inserted. Furthermore, there exists a need for an efficient and easy method of determining the physical properties of fasteners after the fasteners have been used.